Synthesis, Characterization and Modification of Hyperbranched Ultrathin Grafts on Polymer Films, Fibers and Powders

9977911 bergbreter本项目的化学研究将为利用超支化接枝改性聚合物表面带来新的方法。缩聚化学将用于将共聚物、树状大分子和功能胶体连接到含羧酸的底物上。通过碳-碳键完全连接的超支化接枝也将使用Heck和Wittig化学的组合来制备。这些超支化接枝将在聚烯烃薄膜、粉末、胶体颗粒和纤维上制备。所得到的接枝将被设计成对pH值和温度有反应。超支化接枝形成的薄膜界面的进一步修饰将通过共价和离子修饰化学来完成。通过“活的”径向聚合的共价修饰将与在超支化接枝上的“简单”共价接枝进行比较。枝状聚合物、生物聚合物和嵌段共聚物对超支化接枝的离子修饰也将被研究，并与含有单层官能团的中性底物上类似的离子组装过程进行比较。物理和光谱研究将探讨这些移植物的覆盖范围，它们对各种外部刺激的反应性和反应性。这类研究将主要使用荧光、紫外可见、ESR和XPS光谱。这些研究的结果将改进在各种衬底上合成功能薄膜的一般路线。这种表面改性化学将导致新的方法来改善常用聚合物的表面性能。这种改进的表面特性将导致材料具有更好的可印刷性、附着力和生物相容性——这些特性很重要，因为现有材料经过改性，在生物技术和材料科学中具有更大的用途。

9977911BergbreiterThe chemistry in this project will lead to new methods for polymer surface modification using hyperbranched grafts. Condensation polymerization chemistry will be used to attach copolymers, dendrimers and functional colloids to carboxylic acid containing substrates. Hyperbranched grafts completely attached via carbon-carbon bonds will also be prepared using a combination of Heck and Wittig chemistry. These hyberbranched grafts will be prepared on polyolefin films, powders, colloidal particles and fibers. The resulting grafts will be designed to be responsive to pH and temperature. Further modification of the thin film interfaces formed by hyperbranched grafting will be accomplished by covalent and ionic modification chemistry. Covalent modification by "living" radial polymerization will be compared to "simple" covalent grafting on hyperbranched grafts. Ionic modification of hyperbranched grafts with polyelectolyte dendrimers, biological polymers and block copolymers will also be studied and compared with similar ionic assembly processes on neutral substrates containing monolayers of functional groups. Physical and spectroscopic studies will probe the extent of coverage of these grafts, their responsiveness to various external stimuli and their reactivity. Such studies will primarily use fluorescence, UV-visible, ESR and XPS spectroscopy. The result of these studies will be improved general synthetic routes to functional thin films on various substrates. This surface modification chemistry will lead to new methods to improve the surface properties of commonly used polymers. Such improved surface properties should lead to materials with better printability, adhesion and biocompatibility - properties that are important as existing materials are modified to be of increased utility in biotechnology and materials science.